Tank question

[lungs71]

I just picked up a set of aluminum tanks that are setup in doubles. I have two questions I was looking for some thoughts on.

A little background – I currently have a steel HP 100 with a DIN that I got for free, so my regulator is DIN with a k-valve adaptor. I like the DIN, it seams like a better design to me. I plan to dive with aluminum tanks as singles for now until I am a little more skilled. I have 18 dives but still think I need to wait a little until some of my skills are refined a little more. I am in the north east so I either dive with a 7mm wet suite or dry suite with hood and gloves. I am 170lb, and about 6ft tall. Need my shoe size? Only kidding….

So for my questions

When I decide to make the tanks doubles, is there a big issue with doing that with aluminum tanks? I understand the buoyancy differences between steel and aluminum, but is it going to create a major issue? Does anyone out there double up aluminum tanks or am I going to be the only fool??

The manifold is can be split so that I can use the tanks as singles. It also can be converted between DIN and K-valve. Like I noted above I like DIN, do I need to keep the K-valve insert installed since it is a LP tank, or will the fill guys check the tank ratings? I would hate for someone to get injured because I break protocol with a DIN.

Ok, a third question.

I have a Zeagle ranger BC that I really like. It has a 44lb lift and says it is rated for two 120qFt tanks, with some minor strap adjustments. I have read a few posts about lift but for some odd reason my head ends up spinning and I seam to miss the true valid data. Do you think I would be ok with a 44lb lift if I went double?

I have not spoke with my LDS yet, which I plan to do.

Thanks!!!!

 

[Leadking]

I dove double 80's for years. The downside is the buoyancy difference between al and steel cylinders. If you don't mind wearing 10-15 lbs extra weight go with the aluminums. The new 3442 psi cylinders are nice if they're in your budget.

 

[Scared Silly]

Alot of people double AL cylinders. I have a set. They are the way to go for diving a wet suit as you will have some some ditchable weight. (Do a search for more info on this -or better when you are ready seek out an instructor.

As for the manifold. If you have a DIN reg pull the plug out and use it that way. It does not matter. For the higher pressures DIN should be used. I think this is your question.

You can use the Ranger for doubled cylinders but you will need to figure your lift needs separately. Look at the bouyancy calculator that is a sticky in the BCD section. That said it will "probably work". Also you might want to pick up a Zeagle backplate as the Ranger bladder can be used on it (and it only). A backplate with doubles will be more comfortable. I went this route and then switched to a BP for both singles and doubles.

 

[SDAnderson]

When I decide to make the tanks doubles, is there a big issue with doing that with aluminum tanks?

Big is a subjective term but, yes, there are issues. Not necessarily bad, just things you need to be aware of and take into consideration.​

I understand the buoyancy differences between steel and aluminum, but is it going to create a major issue?

Same question as #1, same answer.​

Does anyone out there double up aluminum tanks or am I going to be the only fool??

Lots of people double AL cylinders. Chances are good that any number of them are at least a goofy ​

Like I noted above I like DIN, do I need to keep the K-valve insert installed since it is a LP tank, or will the fill guys check the tank ratings?

If the valves on the tank are DIN/K's (DIN to K convertible) you can remove the donuts without fear of messing anything up - that's why they're there. If you're especially considerate you will make sure that the burst disk is appropriate for the cylinder but you can use whatever valve you want.​

Do you think I would be ok with a 44lb lift if I went double?

Insufficient data but 44lbs of lift is probably adequate. How negative are you at the start of the dive, how much gas are you going to use, how much will suit compression impact your buoyancy, etc. One of the best reasons for diving doubling AL tanks is their inherent positive buoyancy at the end of the dive.​